1. Technical Field
The present invention relates to an optical position detecting device that optically detects the position of a target object and an apparatus provided with a position detecting function that includes the optical position detecting device.
2. Related Art
As an optical position detecting device that optically detects a target object, for example, a device is proposed in which detection light is emitted from a plurality of detection light sources toward the target object through a light transmitting member, and the detection light reflected by the target object is transmitted through the light transmitting member so as to be detected by a light receiving unit. In the optical position detecting device having such a configuration, the position of the target object is detected based on a detection result of the detection light in the light receiving unit (for example, see JP-T-2003-534554).
In addition, a method is also proposed in which a light guiding plate is arranged in an optical position detecting device, detection light emitted from a plurality of detection light sources is output toward a target object through the light guiding plate, and the detection light reflected by the target object is detected by a light receiving unit (see JP-A-2010-127671 and JP-A-2009-295318).
However, the ranges of the optical position detecting devices disclosed in JP-T-2003-534554, JP-A 2010-127671, and JP-A-2009-295318 in which the position of a target object can be detected are narrow. Accordingly, there are many problems to be solved for detecting the position of a target object in a broad area such as a screen face of a projection-type display apparatus, a screen face of an electronic blackboard, digital signage, or the like.
Here, the inventors of the invention propose a method in which a band-shaped flexible substrate having a plurality of light emitting devices mounted thereon is bent so as to position the light emitting devices in different angular directions, and the position of a target object is detected using detection light emitted from the light emitting devices. According to such a configuration, the detection light can be emitted over a wide angle range from the position in which the flexible substrate is arranged, and accordingly, the position of the target object can be detected in a broad area.
However, according to such a method, it takes extensive labor to accurately bend the band-shaped flexible substrate so as to allow the light emitting devices to be positioned in a predetermined direction, and it is difficult to fix the flexible substrate in such a state. Thus, a configuration is considered in which a substrate supporting member having a convex face is prepared, and the flexible substrate is disposed so as to overlap the convex face of the substrate supporting member. However, in a case where the position of the flexible substrate is deviated due to a deviation in the size of the flexible substrate, there is a problem in that it is difficult to detect the position of the target object with high precision due to the deviation in the position of the light emitting devices.